Paroxetine HCl

A to Z Drug Facts

 Actions Blocks reuptake of serotonin, enhancing serotonergic function.

 Indications Treatment of depression, obsessions, and compulsions in patients with obsessive-compulsive disorder (OCD); panic disorder with or without agoraphobia; social and generalized anxiety disorders (as defined in the DSM-IV); posttraumatic stress disorder.

 Contraindications Concomitant use in patients taking MAOIs.

 Route/Dosage

Depression: ADULTS: PO Immediate release: 20 mg/day initially; may increase by 10 mg/day at intervals of greater than or equal to 7 days (max, 50 mg/day). Administer as single daily dose, usually in morning. Controlled release: 25 mg/day as a single dose, usually in the morning (usual dose range 25 to 62.5 mg/day). The dose may be increased in increments of 12.5 mg/day at intervals of at least 1 wk (max, 62.5 mg/day).

Elderly or Debilitated Patients or Patients with Severe Renal or Hepatic Impairment: PO Immediate release: 10 mg/day initially; do not exceed 40 mg/day. Controlled release: 12.5 mg/day initially; do not exceed 50 mg/day. OCD: Adults: PO 20 mg/day initially; recommended dose is 40 mg/day. Administer as single daily dose, usually in morning. Do not exceed max dosage of 60 mg/day. Panic Disorder: ADULTS: PO Immediate release: 10 mg/day initially; recommended dose is 40 mg/day. Administer as single daily dose, usually in morning. Do not exceed max dosage of 60 mg/day. Controlled release: 12.5 mg/day as a single dose, usually in the morning. The dose may be increased in increments of 12.5 mg/day at intervals of at least 1 wk to a max of 75 mg/day.

Elderly or debilitated or patients with severe renal or hepatic impairment: PO Controlled release: 12.5 mg/day initially; do not exceed 50 mg/day. Social Anxiety Disorder: Adults: PO 20 mg/day administered as a single daily dose with or without food, usually in the morning. Usual range is 20 to 60 mg/day.

Elderly or Debilitated Patients or Patients with Severe Renal or Hepatic Impairment: PO 10 mg/day initially; increase if indicated (max, 40 mg/day). Generalized Anxiety Disorder/Posttraumatic Stress Disorder: ADULTS: PO 20 mg/day administered as a single dose with or without food, usually in the morning. Usual range, 20 to 50 mg/day.

Elderly or Debilitated Patients or Patients with Severe Renal or Hepatic Impairment: PO 10 mg/day initially; increases may be made if indicated (max, 40 mg/day).

 Interactions

5-HT₁ agonists (eg, naratriptan, sumatriptan, zolmitriptan): Weakness, hyperreflexia, and incoordination have been reported rarely. Alcohol: Causes additive CNS effects; concurrent use is not recommended. Cimetidine: May increase paroxetine concentrations. Cyclosporine: Concentrations of cyclosporine may be elevated, increasing the risk of toxicity. Cyproheptadine: Pharmacologic effects of paroxetine may be decreased or reversed. Digoxin: May decrease digoxin levels. MAOIs: Can cause serious, sometimes fatal reactions. Do not use concomitantly or within 14 days of each other. P450 system: Coadministration with other drugs metabolized by cytochrome P450 2D6 (eg, certain antidepressants, phenothiazines, type IC antiarrhythmics) or drugs that inhibit this enzyme (eg, quinidine) should be approached with caution. Phenobarbital, phenytoin: May decrease paroxetine concentration; may reduce phenytoin concentration. Procyclidine: Reduction of procyclidine dose may be necessary if anticholinergic effects (ie, dry mouth, blurred vision, urinary retention) occur. Sibutramine: The risk of occurrence of “serotonin syndrome” may be increased. St. John's wort: Sedative-hypnotic effects may be increased. Sympathomimetics (eg, amphetamine): Sensitivity of sympathomimetics and risk of “serotonin syndrome” may be increased. Theophylline: Clearance of theophylline may be decreased by 3-fold; reduce dosage. Elevated theophylline levels have occurred with paroxetine. Monitor theophylline levels when coadministered. Tryptophan: May cause headache, nausea, sweating, and dizziness. Warfarin: Increased risk of bleeding. Zolpidem: The effect of zolpidem may be increased.

 Lab Test Interferences None well documented.

 Adverse Reactions

CARDIOVASCULAR: Palpitation; orthostatic hypotension; hypertension; syncope; tachycardia; chest pain; vasodilation. CNS: Drowsiness; dizziness; insomnia; tremor; nervousness; anxiety; paresthesia; agitation; drugged feeling; confusion; amnesia; vertigo; headache; emotional lability; impaired concentration; somnolence; myoclonus/twitching; hypertonia; CNS stimulation; abnormal dreams/thinking; depersonalization. DERMATOLOGIC: Sweating; rash; pruritus; acne. EENT: Blurred vision; tinnitus; rhinitis; taste perversion. GI: Nausea; dry mouth; constipation; diarrhea; anorexia; flatulence; vomiting; abdominal pain; dyspepsia; increased appetite; decreased appetite; tooth disorders/caries; oropharynx disorder; dysphagia. GU: Ejaculatory disturbance; genital disorders; decreased libido; urinary frequency; breast atrophy; sexual dysfunction/impotence/anorgasma; UTI. HEMATOLOGIC: Leukopenia; anemia; lymphocytosis; leukocytosis; lymphadenopathy; purpura. METABOLIC: Edema; weight gain or loss; thyroid problems. RESPIRATORY: Pharyngitis; cough; bronchitis; rhinitis; yawn. OTHER: Myopathy; myalgia; back pain; asthenia; chills; malaise; fever; myasthenia; arthralgia.

 Precautions

Pregnancy: Category C. LACTATION: Secreted in breast milk. Use with caution. CHILDREN: Safety and efficacy not established. Special risk patients: Use with caution in patients with history of seizure, mania, hypomania, suicidal tendencies, drug abuse, or dependence. Altered platelet function: Altered platelet function or abnormal results from lab studies have occurred. Hepatic/Renal impairment: May increase plasma concentrations of paroxetine; adjust dosage. Hyponatremia: Hyponatremia has occurred. Use drug with caution in elderly patients, patients taking diuretics, and volume-depleted patients.

 Administration/Storage

• Do not give within 14 days of MAOI administration.
• Administer once daily, usually in morning.
• Store at room temperature in well-closed container.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Review for history of liver or kidney disease or seizure disorder.
• Monitor weight weekly.
• Continue suicide monitoring of high-risk patients.
• If headache, nervousness, nausea, somnolence, insomnia, asthenia, dizziness, or sweating occur, report to health care provider.
• Observe for signs of mood change and report to health care provider.
• Make dosage adjustments to maintain the patient on the lowest effective dosage, and periodically reassess the patient to determine the need for continued treatment.

 Patient/Family Education

• Inform patient that improvement with therapy may not be evident for several weeks.
• Emphasize importance of following drug regimen as prescribed.
• Instruct patient to report the following symptoms to health care provider: headache, nervousness, nausea, somnolence, insomnia, asthenia, dizziness, sweating.
• Advise patient to take sips of water frequently, suck on ice chips or sugarless hard candy, or chew sugarless gum if dry mouth occurs.
• Instruct patient to avoid intake of alcoholic beverages.
• Advise patient that drug may cause drowsiness, dizziness, and vertigo, and to use caution while driving or performing other tasks requiring mental alertness.
• Instruct patient not to take prescription or OTC drugs without consulting health care provider.
• Advise women to notify health care provider if pregnant, intending to become pregnant, or are breastfeeding.
• Advise patient to notify health care provider if rash, hives, or a related allergic phenomenon develops.
• Advise patient that drug may cause photosensitivity. Avoid prolonged exposure to the sun and other UV light. Use sunscreen and wear protective clothing until tolerance is determined.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts